This module has been deprecated in favor of Catalyst::Controller::RequestToken.
Please do not use it in new code.
It has known compatibility issues and is absolutely not supported by anyone.
It remains only in case you have existing code that relies on it.

if you loaded Catalyst::Plugin::FormValidator::Simple and fail to validate token, C::P::FormValidator::Simple->set_invalid_form will call automatically in validate_token method (constraint name is 'TOKEN').